The son of the North Carolina death row inmate who wrote a taunting letter about his life of leisure in prison says that his father is mentally ill and "severely depressed."

"No person in their right mind thinks that living in death row is a life of leisure," Danny Hembree III told ABCNews.com about his father. "There's no good explanation for why he wrote that except he's mentally ill."

Rather than living a life of leisure filled with color TV and naps,, the son said his father's life was grueling.

"He talks about the four walls closing in, that the lights are always on and he can't sleep. Death row is a horrible place for anybody to be," Hembree III said. "He's very severely depressed. He has told us that he's depressed. He feels like it's over for him."

Hembree's father Danny Hembree Jr. was found guilty of murdering 17-year-old Heather Catterton in 2009 and was sentenced to death on Nov. 18, 2011.

This week, Hembree, 50, sent a letter to his hometown newspaper The Gaston Gazette about his life at Central Prison in Raleigh, N.C.

"Is the public aware that I am a gentleman of leisure, watching color TV in the A.C., reading, taking naps at will, eating three well balanced hot meals a day," Hembree asked in the letter. "I'm housed in a building that connects to the new 55 million dollar hospital with round the clock free medical care 24/7."

Hembree's son said that the letter does not accurately portray what his father is going through.

"The letter that he wrote, he was just lashing out," Hembree III said. "It's really hard on us and it's really hard on him."

Hembree III said that his father has been diagnosed as bipolar and manic depressive and that he suffered from brain damage when he was born. The Hembree family can only correspond with him through letters and Hembree III said that he father paints a very different picture of his life when he writes to the family.

Hembree has also been accused of killing two other women. One was Randi Dean Saldana, 30, whose burnt remains were found near Blacksburg, S.C., in 2009. The other was Deborah Ratchford, 30, whose body was found in 1992.

He admitted to taking drugs and having sex with Catterton and Saldana on the days they died, but told jurors he did not kill them or dispose of their bodies, according to ABC News' Raleigh-Durham affiliate WTVD. He is scheduled to go on trial for Saldana's killing in March.

Hembree confessed to killing the three women during recorded police interviews, but later said the confessions were an attempt to cover up a string of armed robberies, according to the Gaston Gazette.

Hembree III said that his father was not in his right mind when he made the taped confessions.

"In every one of those confessions on all of those tapes, he was coming off a three-day crack binge. He hadn't slept, he was drunk and highly intoxicated. He could barely hold his head up," Hembree III said.

But Hembree's letter to the paper does not convey the fear and depression his son says he feels.